Meat tenderizing attachment for electric mixers



United States Patent Ofitice 3,tl66,350 MEAT TENDERIZTNG ATTACHMENT FGR ELETRIC MIXERS Edward L. Quiring, 3018 Wisconsin Ave. N., l /iinneapolis 27, Minn. Filed Dec. 23, 1958, Ser. No. 782,482

6 Claims. (Cl. 17-25) This invention relates to reciprocating hammering devices, and in particular to a meat tenderizing attachment for electric mixers.

An object of this invention is a novel meat tenderizing device which is particularly adapted for use with electric mixers, said device being substituted for the removable mixer blades commonly found on present day mixers.

Another object is a meat tenderizer of the class de scribed wherein the rotary driving motion provided by the mixer is transformed into reciprocating vertical movement to enable the device to repeatedly pound or hammer a piece of meat thereunder to render it more suitable for cooking and eating.

Still another object is a device of the class described wherein a spring loaded hammer or jstriker is recoil operated by a rotary drive shaft whose axis of rotation is coaxial with the line of recoil movement.

A further object is a hammering device of the class described wherein a cam and cam followercooperate in response to rotary movement supplied by the electric mixer to compress the spring of a spring loaded hammer or knife and then release the spring to drive the hammer downwardly in a pounding or cutting action.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like reference characters refer to the same or similar parts throughout the several views, and in which:

FIG. 1 is a perspective View of the meat tenderizer of my invention mounted for use on an electric mixer;

FIG. 2 is a cross sectional view of my invention on an enlarged scale taken approximately on the line 22 of FIG. 2; and

PEG. 3 is a vertical-sectional view of the attachment of my invention taken on the line 3 -3 of FIG. 2.

The apparatus of my invention broadly comprises a hammering or impacting body mounted on a rotary drive memberand a carnming mechanism which provides the impacting body with reciprocal pounding movement in response to the rotary motion supplied by the drive memher.

A preferred embodiment of my invention illustrated by the drawings comprises a pair of hammering or impacting members 5 and 5' provided with longitudinal cylindrical bores or recesses 6 and 6' and having a plurality of teeth or cutting edges 7 and 7 extending downwardly from their striking or hammering faces.

Enclosed within the recesses 6-6 are a pair of cylindrical pistons or cams 88 which are rotatably and coaxiaily mounted therein, each of said pistons having a spiral upper camming surface indicated generally by the numerals 9-9', which upper camming surfaces spiral downwardly from their highest point of elevation 1010' to their lowest point of elevation 1111, the direction of descending spiral being the same as the direction of rotation of the respective pistons. The highest and lowest points of the spiral camming surface are interconnected by a vertical wall or drop-off face 24-24' which serves to interrupt or momentarily discontinue the camming action hereinafter to be described so as to release or trigger the hammers for sudden unrestrained spring urged downward movement to obtain the pounding action desired. The pistons are rotated or driven by spindles of the pistons and 3,%t5,356 Patented Dec. 4, 1962 01' cam shafts 1212 to which they are rigidly secured, the spindles being adapted for insertive cooperative driv ing engagement with the drive shafts S-S of the electric mixer M so as to be driven or rotated thereby. Since the drive shafts of most electric mixers now in use rotate in opposite direction to one another, the camming surfaces of the pistons spiral downwardly in opposite direction to one another, but in the same direction as the direc tion of rotation of their respective spindles and mixer drive shafts. In the form shown in the drawings, drive shaft S, spindle 12' and piston 8 are adapted for clockwise rotation, while drive shaft S, spindle 12 and piston 8 are adapted to rotate in counterclockwise direction.

The cams are retained in their respective bores by means of circular removable annular retaining rings 1313 through which the spindles are slidably inserted, the retaining rings being held in place by any convenient means, such as set screws 14-14. Recoil means such as compression springs 1515' are enclosed in the bores beneath the earns, the springs engaging the lower faces pressing against the bottom of the bore to urge the hammers downwardly to provide the pounding action desired.

The upper portion of each bore adjacent the lower face of the retaining rings may be provided with an annular groove 16 16 which, in cooperation with the spindle hubs 17-17 define a bearing race or track for a cam follower or tracer such as spherical ball bearings 18-13 which are seated therein so as to be substantially vertically immovable with respect to the hammers.

To prevent rotation or movement of the ball bearings around the circumference of the annular grooves in the direction of rotation of their respective pistons, retaining means such as balls 19-49" are provided which partially project into the annular grooves through an opening provided therein by horizontally disposed recesses 20-40 which are aligned substantially tangentially to the annular grooves and extend from the outer face of the hammer body inwardly in a direction substantially parallel to the direction of rotation of the pistons. The retaining balls are held in place by compression springs 21-21 which in turn are held in the recesses as by plugs 22--22', the purpose of this particular alignment and arrangement to be hereinafter explained.

To transform the rotary motion provided by the mixer through the spindles and the pistons into reciprocatory vertical movement, means must necessarily be provided to prevent rotary motion of the hammers. One means is to provide a dove tail connection as shown at 23, which connection prevents rotary motion of the hammers but permits them to move or slide freely vertically up and down with respect to one another. Another important feature of this interlocking arrangement represented by the dove tail is that it prevents vertical misalignment of the hammers with respect to each other which might result if this interlocking feature were not provided. Although a dove tail connection has been shown and described, it is to be understood that I do not wish to be limited to this specific arrangement, and include as part of my invention any interlocking arrangement which permits free vertical movement of the hammers with respect to each other while at the same time preventing misalign- 'ment of said hammers.

In operation, the spindles of the abutting and/or slidably interconnected hammer bodies are inserted in the proper drive shafts SS of the mixer so as to be cooperatively and drivingly engaged therewith, the proper drive shaft in the illustrated form being the one which rotates in the same direction as the direction of descending spiral of the piston with which it is drivingly engaged. The hammers are vertically disposed so that their striking balls 1'9-19 so that they faces and the cutting edges projecting therefrom are substantially horizontally disposed above the meat to be tendered and in slightly spaced relationship thereto or in contact therewith. Power is then supplied to the mixer, which causes the pistons to rotate at relatively high speeds. As the pistons rotate, the'ball bearings 13-18 are held against the retaining balls 19-19" to prevent their circumferential movement in the annular grooves 1616' and frictionally engage the spiral camming surfaces of the pistons as they pass beneath the bearings, the bearings tracing the path of the camming surfaces progressively from the lowest elevation point 11 to the highest elevation point 1.0. Since the pistons are not vertically movable, the camming action of the ball bearings tracing the spiral surface of the pistons from the lowest to the highest point causes or forces the hammers 5 to progressively rise vertically until the high point of the camming action is reached, the rising of the hammers causing springs 15-15 to become increasingly compressed in the bores. Upon reaching the high points -1t) of the spiral surfaces, the ball bearings fall off the high points 10-16 to the low points 11-11. This falling off of the bearings 18-48 momentarily'discontinues the camming action and releases the hammers,- for unrestrained downward movement, which hammers are urged instantaneously downwardly against the meat by the compressed springs 15-45, which are also released by the bearings falling off high point into lowpoint '11 and which provide a recoil action for the hammers. The camming action is then repeated as previously described so long as rotary power is supplied to the pistons. In the drawings, the follower 18 is engaging the spiral camming surface 9 at its lowest point 11 and hammer 5 is at the lowest point of its stroke, and is prepared to rise to the peak of its stroke as illustrated by the dotted lines. Conversely, follower 18' is shown engaging the spiral camming surface 9 at its highest point is, the hammer 5' having been raised to the peak of its stroke just prior to its being released for unrestained downward movement to theposition shown by the dotted lines. Although the drawings present the two hammering units in out of phase relationship to better illustrate the relative relationship of the various elements at the maximal and minimal points of the camming action, they need not necessarily be so, but each may be in phase with one another so as to pound the meat simultaneously. However, the out-of-phase action of the two hammers 5 and 5' in the form illustrated is preferred, since the alternate pounding and cutting by the hammers partially shifts the meat back and forth under the hammers, thereby presenting a slightly different exposed portion of meat to the hammers each time, and thereby obtaining a more thorough tendering action. The relatively high speed of rotation of the pistons, causes this recoil cycle to be repeated many times in the space of a single minute, thereby providing a very rapid pounding or hammering of the meat by the cutting edges of the hammers. This repeated cutting of the meat by the cutting edges cuts and exposes the fibers of the meat, rendering it considerably more suitable for cooking and eating, transforming relatively inexpensive cuts of meat into a quality usually found only in more expensive cuts of meats. M

It is anticipated that users of my device will occassionally accidentally insert the spindles in the wrong drive shaft of the mixer, thereby providing rotary drive to the pistons in a direction opposite to that for which they are designed. To prevent damage to either the device of my invention or the electric mixer in such a circumstance, 1 have provided the safety feature previously described of resiliently mounting the retaining are immovable when the ball bearings 18-18 press against them in the direction of proper rotation, but will yield when the bearing is pressed against them from the opposite direction when driven in reversed direction, thus permitting the bearings to pass towards said shaft in response and abruptly release said body member for free biased by the retaining balls and follow the annular groove with no camming action or damage taking place.

From the foregoing, it can be readily seen that I have provided a novel and very useful meat tenderizing attachment for electric mixers now available and in use. The method of attachment is easy, the device is inexpensive, particularly for those who already have an electric mixer, the tenderizing results are quick and effective, and the possibilities of damage due to accidental improper attachment are avoided by the safety features hereinbefore described.

It will, of course, be understood that various changes may be made inthe form, details, arrangement and proportions of the various parts without departing from the scope of my invention.

Although the forgoing description has emphasized the use of my invention for meat tendering purposes, it is to clearly understood that my invention is not limited to such a'use, and may be applied to any operation where repeated hammering orpounding is desirable or neces sary, including the chopping of foodstuffs such as peanuts and onions. 7

The illus't'ration of the use of my device with a mounted electric mixer isby way of example, and not limitation, and it is to be further understood that the device'of my invention may be mounted on a portable type electric mixer or'any other apparatus which provides rotary motion 'to "the drive shaft.

What is claimed is:

1. In combination, a power unit having a pair of axially parallel juxtaposed rotatable drive shafts and motor means for rotating said shafts, reciprocating device's mounted in juxtaposition to each other on each of said shafts, each of said devices including a body member, means for rotatably receiving said shaft and suspending said body member therefrom for reciprocating movement of said body member axially of its shaft, spring means continuously biasing said body member away from its shaft, means for engaging and holding said body members against rotative movement, and camming means actuated by said drive shaft and adapted to repeatedly move said body member axially toward said shaft in response to the rotation of said shaft and abruptly release said body member "for free biased movement thereof away from said shaft.

2. The combination set forth is claim 1, wherein said power unit includes a pair of juxtaposed rotatable chuck members 'driven by said motor means and adapted for rotation about parallel axes of rotation and further adapted to disconnectibly drivingly engage and hold said drive shafts.

3. In combination, a'power unit having a pair of axially parallel juxtaposed rotatable drive shafts and motor means for rotating said shafts, reciprocating devices suspended in juxtaposition from each of said shafts, each of said devices including a body member having means for rotatably receiving and journaling itsshaft and suspending said body member therefrom for reciprocating movement of said body member axially of said shaft, spring means continuously biasing said body member away from its shaft, camming means actuated by said drive shaft and adapted to repeatedly move 'said body member axially to the rotation ofsaid shaft movement thereof away from said shaft, said juxtaposed body members being in abutting axially sliding relationship to one another, each body member preventing rotational movement of the other body member.

4. In combination, a power unit including a pair of juxtaposed rotatable tool chucks rotatable about parallel axes of rotation in opposite direction and adapted to disconnectibly drivingly engage and hold a drive shaft member and motor means for rotating said chuck members, reciprocating devices adapted to be mounted on said chuck members, each of said devices comprising a drive shaft adapted for disconnectible driving engagement with one of said chucks, a body member, means for rotatably receiving said shaft and suspending said body member therefrom for reciprocating movement of said body member axially of its shaft, spring means continuously biasing said body member away from its shaft, means for engaging and holding said body members against rotative movement, a cam element and a cam follower element, one of said elements being drivingly connected to said shaft for rotation therewith, the other element being engaged with said body member and said cam for reciprocating said body member axially of said shaft in response to the rotation of said shaft, said cam providing a camming surface progressively rising from a low to a high portion and abruptly terminating in a shoulder connecting the high and low portions of the camming surface, means for holding said other member permitting relative movement between said elements when said shaft is rotated in one direction, said relative movement causing said follower to progressively trace said camming surface from the low to the high portion thereof to move said body member axially towards said shaft and release said body member for free biased movement away from said shaft when said follower reaches said shoulder and passes from the high to the low portion of the cam, and means releasing one of said elements from camming engagement with it respective member to deactivate said body member when said shaft is rotated in a direction opposite to that first mentioned.

5. In combination, a power unit including a pair of juxtaposed rotatable tool chucks rotatable about parallel axes of rotation and adapted to disconnectibly drivingly engage and hold a drive shaft member and motor means for rotating said chuck members, reciprocating devices adapted to be mounted on said chuck members, each of said devices comprising a body member having a cylindrical bore, a cylindrical cam element having a helicoidal camming surface terminating abruptly in an axially disposed shoulder between the high and low portions of the cam, said cam element being rotatably mounted in said bore, an elongate drive shaft having one end adapted for driving engagement With one of said chucks and the other end adapted for driving engagement with said cam, means carried by said body member rotatably receiving and journaling said shaft and suspending said body member therefrom for reciprocating axial movement thereon, spring means continuously biasing said body member axially away from said shaft, and a cam follower drivingly engaged with and held by said body member and adapted to trace said camming surface from the low to the high portion thereof when said shaft is rotated in one direction to thereby move said body member axially towards said shaft and releasing said body member for free biased axial movement away from said shaft when the cam follower reaches said shoulder and passes from the high to the low portion of the cam, the body members on said shaft being in abutting juxtaposed position and freely axially slidable with respect to each other, said engagement of said body members preventing rotational movement of said bodies.

6. The combination set forth in claim 5, including means for releasing one of said elements from driving engagement with its respective member when said shaft is rotated in a direction opposite to that first mentioned to thereby prevent camming action and deactivate said devices while said shaft is rotating in said last named direction.

References Qited in the file of this patent UNITED STATES PATENTS 1,273,873 Kollock et a1 July 30, 1918 2,200,035 Meyer May 7, 1940 2,205,133 Bragg June 18, 1940 2,518,429 Moorhead Aug. 8, 1950 2,534,943 Bergeson Dec. 19, 1950 2,559,270 Abbott July 3, 1951 FOREIGN PATENTS 563,166 France Sept. 20, 1923 

